Method of making a stair tread and the like



0a. 15, 1929. H, A, WELCOM 1,731,514

IETHOD OF IIAKING A' STAIR TREAD AND THE LIKE Filed. Dec. 5, 1928 IJC I] IN VEN TOR.

M' TTORNEY.

Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE HAROLD ASHLEY WELCOME, OF LOWELL, MASSACHUSETTS, ASSIGNOR TO AMERICAN MASON SAFETY TREAD COMPANY, OF LOWELL, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS METHOD OF MAKING A STAIR TREAD AND THE LIKE Application filed December 5, 1928. Serial No. 324,050.

This invention relates to the method of making a stair tread or the like and has for an object to produce by certain steps a stair tread which embodies a base havlng a dovetailed groove filled with a material tendlng to prevent slipping.

It is well'known that to produce a strip of material provided with a clove-tailed groove certain mechanical problems are presented, whether the strip be cast or rolled. In the case of casting, it is impossible to withdraw the mold from the dove-tailed pattern and 1n the case of rolling it is impossible to roll at a single operation a strip having a dove-tailed groove. The present inventlon 1S, therefore, directed to and has for an object the production of the strip of dove-tailed material by rolling or casting, or combination of the two mechanical devices, and in a new and improved manner.

A further object of the lnventlon 1s to provide a method whereby a strip may be formed as a dove-tailed retaining member and simultaneously the dove-tailed groove filled with a relatively softer metal tending to prevent sliping of the user thereon.

With these and other objects 1n vlew, the invention comprises certain novel steps 1n the method of making a stair tread, as disclosed in the drawings and hereinafter described and claimed. I

In the drawings:

Figure 1 is a perspective view of a strip of material as it is produced by the first step of the process whether such first step consists of casting or rolling.

Figure 2 diagrammatically discloses the second step of the operation wherein, by the use of properly coordinating rollers, the 1nitial strip disclosed at Figure 1 is formed wlth a dove-tailed groove.

Figure 3 is a perspective view of the dovetailed strip filled with a mater al orlginally plastic tending to prevent slipping.

Figure a is a diametrlcal v1ew show ng the steps and conventional means for slmultaneously producing the dove-tailed slot and filling with a relatively soft metal.

Figure 5 is a transverse sectional view showing the completed strip.

Figure 6 is a modification showing a strip which, when completed, will provide adjacent and parallel slots with remotely positioned dove-tailed shoulders.

Figures 7 and 8 are respectively modifications of the strip and the rollers employed for converting the strips into strips with clovetailed grooves, said strips being provided with different types of nosing to produce a stair nosing.

Like characters of reference indicate corresponding parts throughout the several views.

The first step in the method which forms the subject matter of this invention is the production of a strip of relatively hard metal having a groove therein limited by the bottom wall 10 and side walls 11 and 12, the latter of which initially are substantially parallel, and the former 10 is conveXed. This strip is produced in any well known manner and the initial production of this strip forms no part of the present invention.

The strip shown at Figure 1 is, as the first step which enters into the present invention, passed between rollers 13 and 14, the roller 14: being an ordinary cylindrical roller, and the roller 13 being properly proportioned in length so that, when the convex wall 10 of the strip is depressed to a substantial planarit-y, it is not too long to co-a'ct with the walls 11 and 12 which are by the compression inclined toward each other. The resulting strip is .shown at Figure 3, the groove now being clove-tailed by the convergence of the walls 11 and 12, and as shown in this figure a material 15 is filled into the dove-tailed groove. This material 15 is intended to be any granular material which is introduced in a plastic state and hardens and presents a non-slipping surface for use.

However, it is often desirable to use instead of the plastic material a relatively softer metal such as for instance lead, and the process includes in that case the use of the lead first in the form of a wire 16 which is fed with the strip between rollers 17 and 17 which exerting pressure simultaneously flattens the wire 16 and by the pressure exerted also flattens the convexed bottom wall of the strip so that the resulting structure comprises a body 16 of the relatively soft metal compressed into and as the complement of the dove-tailed groove and held therein by the overhang of the walls 11 and 12.

AtFigure 7 the structure is substantially identical with the foregoing except that, at one side, a nosing 18 is applied and in this case the roller 19 will be of such length and so placed relative to the strip that the nosing will overhang one end of the roller as indi cated so that, when pressure is exerted upon the convexed wall 10, it will produce the same effect as hereinbefore described.

At Figure 8 a different type of nosing 20 is shown with a different type of co-acting roller 21, other steps however being identical. At Figures 7 and 8, the side walls have been shown initially as divergent but it is to be understood that this is merely a matter of degree and that the walls may be any angle to the convexed base other than convergent.

The type shown at Figure 6 will be readily understood without further explanation.

What I claim to be new is:

1. The method of making a stair tread or the like, consisting in employing a strip of material having an upwardly convexed bottom wall and non-converging side walls exerting pressure on the convexed wall to compress said convexed wall to substantial planarity, and the side walls to convergence and filling the groove produced thereby with an anti-slip material.

2. The method of making a stair tread or the like, consisting in employing a strip of relatively hard material having a groove therein, the bottom wall of which is upwardly convexed and the side walls non-converging,

introducing into the groove and upon the convexity a relatively softer metal, and exerting pressure upon the relatively softer metal to simultaneously compress the convexed wall to substantial planarity and the slde walls to convergence and the softer metal to assume a complete filling of the groove produced thereby.

4. The method of making a stair tread or the like, consisting in employing a strip of material having a' groove presenting an upwardly convexed bottom wall and non-converging side walls, introducing a relatively softer metal into the groove and simulta neously compressing the two materials, producing a convergence of the outer walls of the harder material and a complete filling of the groove of the softer material.

41-. The method of making a stair tread or the like, consisting in employing a strip of material having a groove defined by upwardly convexed bottom wall and non-converging side walls, introducing into the groove and upon the convexity a wire composed of material softer than the material containing the groove and passing the combined material between 

